/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 */

#include <errno.h>
#include <fcntl.h>
#include <glob.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>

#include <libcfs/util/param.h>

static double timenow(void)
{
   struct timeval tv;

   gettimeofday (&tv, NULL);
   return (tv.tv_sec + tv.tv_usec / 1000000.0);
}

typedef struct {
        unsigned long        msgs_alloc;
        unsigned long        msgs_max;
        unsigned long        errors;
        unsigned long        send_count;
        unsigned long        recv_count;
        unsigned long        route_count;
        unsigned long        drop_count;
        unsigned long long   send_length;
        unsigned long long   recv_length;
        unsigned long long   route_length;
        unsigned long long   drop_length;
} counters_t;

static unsigned long long subull(unsigned long long a, unsigned long long b)
{
	if (a < b)
		return -1ULL - b + a + 1;

	return a - b;
}

static unsigned long long subul(unsigned long a, unsigned long b)
{
	if (a < b)
		return -1UL - b + a + 1;

	return a - b;
}

static double rul(unsigned long a, double secs)
{
	return (double)a/secs;
}

static double rull(unsigned long long a, double secs)
{
	return (double)a/secs;
}

static void do_stat(int fd)
{
   static char  buffer[1024];
   static double last = 0.0;
   static counters_t old_counter;
   double now;
   double t;
   counters_t new_counter;
   counters_t counter;
   int    n;

   lseek (fd, 0, SEEK_SET);
   now = timenow();
   n = read(fd, buffer, sizeof(buffer) - 1);
   if (n < 0)
   {
      fprintf (stderr, "Can't read statfile\n");
      exit (1);
   }
   buffer[n] = 0;

   n = sscanf(buffer, "%lu %lu %lu %lu %lu %lu %lu %llu %llu %llu %llu",
	       &new_counter.msgs_alloc, &new_counter.msgs_max,
	       &new_counter.errors, 
	       &new_counter.send_count, &new_counter.recv_count,
	       &new_counter.route_count, &new_counter.drop_count,
	       &new_counter.send_length, &new_counter.recv_length,
	       &new_counter.route_length, &new_counter.drop_length);
   if (n < 11)
   {
      fprintf (stderr, "Can't parse statfile\n");
      exit (1);
   }

   if (last == 0.0) {
                printf("M %lu(%lu) E %lu S %llu/%lu R %llu/%lu F %llu/%lu "
                       "D %llu/%lu\n",
		   new_counter.msgs_alloc, new_counter.msgs_max,
		   new_counter.errors,
		   new_counter.send_length, new_counter.send_count,
		   new_counter.recv_length, new_counter.recv_count,
		   new_counter.route_length, new_counter.route_count,
		   new_counter.drop_length, new_counter.drop_count);
   } else {
	   t = now - last;

	   counter.msgs_alloc = new_counter.msgs_alloc;
	   counter.msgs_max = new_counter.msgs_max;

	   counter.errors = subul(new_counter.errors, old_counter.errors);
	   counter.send_count = subul(new_counter.send_count, old_counter.send_count);
	   counter.recv_count = subul(new_counter.recv_count, old_counter.recv_count);
	   counter.route_count = subul(new_counter.route_count, old_counter.route_count);
	   counter.drop_count = subul(new_counter.drop_count, old_counter.drop_count);
	   counter.send_length = subull(new_counter.send_length, old_counter.send_length);
	   counter.recv_length = subull(new_counter.recv_length, old_counter.recv_length);
	   counter.route_length = subull(new_counter.route_length, old_counter.route_length);
	   counter.drop_length = subull(new_counter.drop_length, old_counter.drop_length);

	   printf ("M %3lu(%3lu) E %0.0f S %7.2f/%6.0f R %7.2f/%6.0f F %7.2f/%6.0f D %4.2f/%0.0f\n",
		   counter.msgs_alloc, counter.msgs_max,
		   rul(counter.errors,t),
		   rull(counter.send_length,t*1024.0*1024.0), rul(counter.send_count, t),
		   rull(counter.recv_length,t*1024.0*1024.0), rul(counter.recv_count, t),
		   rull(counter.route_length,t*1024.0*1024.0), rul(counter.route_count, t),
		   rull(counter.drop_length,t*1024.0*1024.0), rul(counter.drop_count, t));
   }

   old_counter = new_counter;
   fflush (stdout);

   lseek (fd, 0, SEEK_SET);
   last = timenow();
}

int main(int argc, char **argv)
{
	int interval = 0;
	glob_t path;
	int fd;

	if (argc > 1)
		interval = atoi(argv[1]);

	if (cfs_get_param_paths(&path, "stats") != 0) {
		fprintf(stderr, "LNet stats not available\n");
		return 1;
	}

	fd = open(path.gl_pathv[0], O_RDONLY);
	if (fd < 0) {
		fprintf(stderr, "failed to open '%s': %s\n", path.gl_pathv[0],
			strerror(errno));
		cfs_free_param_data(&path);
		return 1;
	}
	cfs_free_param_data(&path);

	do_stat(fd);
	if (interval == 0)
		return 0;

	while (1) {
		sleep(interval);
		do_stat(fd);
	}
	/* Never reached */
}
